Policy | benefit for using tcl

Hello, maybe I am asking this the wrong way but here we go... to have a http-https redirect using policies instead irules, you need to define the location (this is based on https://support.f5.com/csp/article/K26312346)

In BIG-IP 12.1.0 and later, 
location:
tcl:https://[getfield [HTTP::host] ":" 1][HTTP::uri]

Now, the question is the tcl option, what benefits it brings to the action?

Please advise

Thank you